Pneumatic hammer.



H. SCHUMACHER. PNEUMATIC HAMMER. v APPLUATION FILED JULY 6, 1909. 1,044,263. Patented Nov'. 12, 1912.

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H. SCHUMAGHBR. PNBrnwwrm HAMMER. APPLICATION FILED JULY 6, 1909.

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../J /Z M i i Z HENRY SCI-IUMACHER, 0F DENVER, COLORADO.

PNEUMATIG HAMMER.

Speccation of Letters Patent.l

Patented Nov. 12., 17912.

Application am my 6,1909. serial No. 506,138.- v

To all whom it 'may concern.' Y

Be it known that I, HENRY SCHUMACHER citizen of the United States, residing in the city and county ,of Denver and State of Colorado, have invented'certain new and useful Improvements in Pneumaticl Hammers; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and .use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

My invention relates to Aimprovements in pneumatic hammers, my object being to provide a construction of this class, which shall be comparatively simple, and therefore of economical construction, and which at the same tim-e shall be exceedingly efficient in operation.

In my improved construction the hammer reciprocates in an inner casing or sleeve, which constitutes the valve, which itself has a limited degree of reciprocating movement. Shortly before the hammer reaches the limit of its stroke. in either direction', provision is made for shifting the movable sleeve, whereby the live motive fluid is cut olf from the cylinder upon one side of t-he hammer, and caused to enter the same on the op-v posite side, for producing the return'movev ment.

Having briefly outlined my improved con-v struction I will proceed to describe the same in detail, reference being made to the accompanying drawing in which is illustrated an embodiment thereof.

In this drawing: Figure 1 is a side eleva tion of my improved pneumatic hammer.y

y F ig. lis a cross section taken on the line ration of the valve sleeve. Fig. 5 is a vertical longitudinal section taken through the complete tool, the hammer and valve sleeve being shown at their forward limit of movement. Fig. 6 is a similar view, showing the valve sleeve at its rearward limit of movement and the hammer ready to make the return or rearward Stroke.

The same reference characters represent the same part in all the views.

Let the numeral 5 designate the cylindrical body of the tool which as shown inv the drawing has a slightly tapering for- Ward extremity 6. The rear end of this body portion is threaded as shown at 7, to enter a threaded socket formed in the for- Yward part 8, of the handle member 9. The

rear extremity of the body member is lclosed by a head 10, whose outer face engages the bottom ofthe socket, while its inner face is shouldered or offset as shown at 12,. the oflset member entering the rear extremity of the bpdy ofthe cylinder. This cylinder is hollow, and provided with a cylindrical chamber 14, in which is located a valve sleeve 13, whose rear extremity is closed by a head 1 5, its forward extremity being open.

Within the valve sleeve is located the ham,- mer 16, which is mounted to reciprocate freely therein., When this hammer reaches the limit of its forward stroke, it engages the rear end of a tool 17, which protrudes into the hammer chamber sutlieient-ly for the purpose. The shoulder of the cylinder is provided with forwardly and rearwardly located exhaust ports, designated 18 and 19 respectively, and with induction passages 2O and 21 respectively. The passage 20 registers with a port 22 formed in the flange of the head-f 10. 4This passage also registers with a circumferential groove 23, formed in the'handle member just in the rear of the head 10, when the parts are assembled.

The ,passage 20, together with the port 22 and the groove 23, are in communication with a relatively large induction passage 24,

formed in the handle member and'co1nmunicating with a chamber 25, formed in the same member, and in which is located a piston valve 26, acted upon by a coil spring 27, whereby the valve 26 is normally held in position to shut off the air or other motive fluid. This valve is provided with a stem 28, Whose rear extremity protrudes into a cavity 29, formed in the handle member, and into which protrudes an arm 30 of a lever 31, fulerumed at 32. The upper arm 33 of this lever, is conveniently located to be .pressed by the hand of the user of the tool,

for the purpose of throwing the lever to the position shown in Fig. 6, whereby the valve 26 is shifted to open the passage 24,'leadin to the chamber '25, the latter being supplied ing from the source 0f supply not shown.

` The valvofsleeve 13, 1s provided with a.

with motive iiuif from a conduit 34, leady 38 respectively. When the hammer is at itsv number of ports "dtQignated 35,5 36, 37 and forward limit of movement, the 'motive fluid enters the hammer chamber fromthe passage 20, by way of a circumferential groove 39, which is in communication with the port 35 of the valve sleeve. When the hammer is in the aforesaidposition', the motive fluid .acts upon the shoulder. 40, to impart the chamber exhausts through the portr 38 of the hammer sleeve, a circumferential groove 42,

formed in the cylinder and the exhaust port 19. J ust Abefore the hammerreaches its rearward limit of movement, and after it has passed the port 38 of the valve sleeve, the air cushions between the hammer and the rear -head of the valve sleeve, whereby the latter is caused'to move rearwardly until the head of the sleeve engages the inner surface of the headv 10,of the cylinder. In the meantime the motive fluid in the rear of the head 15 of the sleeve, has leaked out into the circumferential groove 42 of the cylinder, through relatively smallv motive fluid passages 43, formed in the wall of the sleeve and their inner extremities 44, lead to the circumferential groove 42. Aft-er the valve sleeve, together with the hammer, have reached their rearward limit of movement, the -motive fluid enters a circumferential groove 45, formed in the wall of the cylinder and communicating with the port- 36, formed in the rear extremity of the valve sleeve. At this time the exhaust is cut olf,

since the port 38 of the sleeve is out of register with the circumferential groove 42, formed in the inner wall of the cylinder.

.As the hammer 16, moves forwardly, just before itl reaches its forward limit of movement, it uncovers a port 46, formed in the valve sleeve and communicating/with a circumferential groove 47, formed inthe wall of the cylinder. From this groove a passage 48 leads rearwardly and communicates with a port 49, leading to a space 50, formed between the head 15 of the valve sleeve and the head 10 of the cylinder,-hence/the live motive fluid is allowed to pass tothe rear (.f the valve sleeve, whereby the latter is shifted from the position shown in Fig. 6, to its forward position as shown inl Fig. 5. During this movement of the valve sleeve the hammer moves forwardly with it, and as' the latter strikes the tool, the motive Huid is allowed to enter the hammer chamber forwardofthe hammer, whereby the latterpis caused to move rearwardly,r thus keepingup or maintaining the proper reciprocating movementf As soon as the valve sleeve is moved forwardly, its rear head 15-moves to a position to cut olf communication between the live motive fluid and the hammer chamber in the rear of the hammer, at the same time the valve sleeve is in position to allow the motive fluid in the rear of the chamber to exhaust through the port 38 to circumferential groove-42, and to port 19. It will also be understood that' as soon as the valve sleeve reaches its rearward limit of movement the induction port 35 of the said sleeve, is moved out of register or communication with the live fluid passage 36, whereby the live air is cut off from the hammer chamber in frontl of the hammer, and the -motive fluid within the chamber in front of the hammer allowed to exhaust through the port 18.

From the foregoing description the use and operation of my improved pneumatic hammer will be readily understood. 'As

suming that the parts are in the position shown in Fig. 5, the user of thehammer by pressing the bit or tool against the part upon which it is to be used, will force the said bit into the hammer chamber against the hammer, and move the latter rearwardly sufliciently to allow the live motive fluid to pass in front of the shoulder 40, of the hammer.`

As-soon as this occurs the lever 31 will be thrown by the hand of the user to the position illustratedl in Fig. 6, whereby the piston valve 26, is moved forwardlyl against its spring 27, sufficiently to open the passage 24, through which the motive fluid travels to the circumferential groove 23, thence through the port 22, to the passage 36, and through the said passage to the circumferential groove 39, and thence through the port 35 to the hammer chamber forward of the shoulder 40 on the hammer. This motive fluid acting on the said shoulder drives the hammer rearwardly, and when it has nearly reached its rearward limit of movement the air cushions between the rear end of the hammer and the head 15 of the valve sleeve, whereby the latter is forced rearwardly against the rear head of the cylinder, the air in the meantime having leaked out from the space 50, through the relatively small passages 43, as heretofore explained. As soon as this occurs the live air is allowed to enter the hammer chamber from the circumferential groove 23, through the pas sages 20 and 21 to circmnferential groove sleeve. This live air then acts on the rear -end of the hammer to drive the latter for wardly, and after the hammer has uncov- .ered the port 46 in the rear of the hammer the motive fluid 'passes to the rear of the valve sleeve through the passage 48, and the port 49, and this motive fluid acting on the valve sleeve causes the latter to move forwardly with the hammer. whereby the live motive fluid is out of? from the hammer ico lll)

amaca chamber in the rear of the hammer, and the air 1n said chamber in thelrear of the hammer allowed to exhaust in a vvmanner heretofore explained. In the meantime cmmunication is opened between' the live air and the hammer chamber in front of the hammer, to move the latter rearwardly and the operations heretofore described in detail are repeated.

The forward extremity of the cylinder is provided with an interior shoulder 51, which is engaged by a yielding buffer 52, against which the forward extremity of the hammer may strike when the lat-ter reaches its forward limit of movement. When in this position however, the hammer cuts off the live motive fluid from the forward extremity of the hammer chamber, and kin order to start the tool it is necessary to press the bit against the material to be acted thereby, and shove the bit inwardly against t-he hammer, whereby the latter is moved rearwardly su'iciently to uncover the inlet port 35 of the valve sleeve, 'to allow the live motive Huid to enter'the hammer chamber forward of the hammer, in order to act upon the latter to move it rearwardly. It will therefore be understood that in the regular operation of the device the hammer does not reach its forward limit: of movement, and consequently does not strike the buffer 51,-- this however occurs when the bit or tool 17 moved away from the rock or other substance upon which it acts, since in that event the hammer will move forwardly under thel influence of the motive fluid in its rear, until it comes in contactwith the buffer thus shutting olf the live motive fluid and stopping the reciprocation of the hammer.

Having thus described my invention .whatI l claim is:

l. A pneumatic hammer comprising av through the port-s and passages of the cylin-- der and valve sleeve, the forward extremity of the valve sleeve being open to allow the hammer to act upon the bit lor tool, the rear extremity of the said sleeve being closed, the said sleeve having a port approximately centrally located, the cylinder having a circumferential passage communicating with the said ort, and a longitudinally disposed passage eading rearwardly from` the circumferential passage, the reai extremity of the longitudinally disposed passage, communicating with the rear end of the cylinder chamber, whereby the live motive fluid in the rear of the hammer is allowed to pass to the rea-r of the valve` sleeve to move the latter forwardly after' the hammer has moved forwardly far enough to uncover the said port in the valve sleeve, the rear c ndf of the said sleeve having restricted passages communicating at their rear extremi- 7f ties with the rear extremity of the cylinderl chamber, and at their forward extremitieswith one of the circumferential grooves of." the cylinder to allow the motive fiiiid to gradually pass 'through the rear portion of the hollow cylinder to permit the valve sleeve to move rearwardly as the/'hammer approaches its rearward limit of movement, substantiallyas described.

2. A pneumatic hammer comprising a hollow cylinder, avalve sleeve mounted to have a limited degree of reciprocation in the cylinder, the cylinder and the sleeve having coperating inlet nand exhaust ports, the cylinder having circumferential and longitudinally disposed passages, the circumferential passages being disposed upon the inner surface-lof the cylinder, and in communication with the inlet and exhaust por-ts'. of the ,cylinder and sleeve, the valv/e sleeve formin'g` o-ne wall ofthe circumferential passages, a hammerv located within the valve sleevel and adapted to reciprocate ther in under the influence oft-he 11i-'e motive fliid introduced through the ports and passages of the cylinder and: valve sleeve, the for ward extremity of the valve sleeve beingy open to allow vthe hammer to act upon the bit or tool, the said sleeve having a` port approximately cent-rally located, the said port beingadapted to be brought. into communication with one of the circumfermoved lforwardly far enough to uncover the said port in the valve sleeve,'substantially as described. f

3. A pneumatic hammer comprising a cylinder, a valve sleeve itlounted to have a liniited reciprocation in the sleeve, the cylinder and the sleeve having cooperating inlet and exhaust ports, the cylinder having circumferential assaffes adiacent the valve sleeve and communicating respectively with the inlet and exhaust ports of the sleeve and cylinder,- and a hammer located within the valve sleeve, `and adapted to reciprocate therein under the influence of the live motive Huid introduced through the ports and BEST VLBLE COPY passages .of the cylinder and valvesleeve, substantiallyas described.

4. A pneumatic hammer comprising a hollow cylinder and a reciprocable valve sleeve mouiited therein, the inner wall of the cylin- V4der having circumferential passages adjacent the valve sleeve, the valvesleeve and the cylinder having inlet and exhaust ports adapted to be brought into and out of communication @with the said circumferential passages,.and means for introducing Huid into -the valve sleeve through the said inlet ports of the cylinder and valve sleeve for op- .erating the hammer, for the purpose .set

I of the cylinder and valve sleeve, the forward extremity, of the valve sleeve being open to allow the hammer to act .on the bit or tool, the said valve sleeve having aport approximately centrally located, the cylinder having a passage communicating with the said port, the said` passage leading rearwardly therefrom and communicating with the rear end of the cylinder chamber, whereby the live motive fluid in' the rear of the hammer is allowed to pass to the rear of the valve sleeve to allow the latter vto move forwardly after the hammer has moved forwardly far enough to uncover the said port in the valve sleeve, the rear end of the sleeveA having restricted passages communicating at their rear extremities with the rear4 extremity of the cylinder in the rear of the valve sleeve,

and at their forward extremity with one of the exhaust passages of the cylinder to Aallow the motive fluid to gradually pass from the re'ar portion of the hollow cylinder, to permit the valve sleeve to move rear-` wardly as the hammer approaches its rearward limit of movement.

46. A pneumatic motor, comprising a hollow cylinder, a valve sleeve mounted to retherein under the influence of the'live mo-y tive liuid introduced through the ports of the cylinder and the valve sleeve, the Vsald valve sleeve having a port approximately I centrally located, the motor havmg a passage conmunicating with said port, said passage leading rearwardly therefrom and communicating with the rear end of the hollow cylinder, whereby the live motive luid in the rear of the hammer is allowed to pass to the rearof the valve sleeve to move the latter forwardly after the hammer has moved forwardly far enough to uncover said port in the valve sleeve, the motor having a restricted passage communicating at its rear extremity with the rear extremity of the hollow of the cylinder and at its forward extremity with one ci the exhaust ports of the motor to allow the motive fluid to gradually pass from the rearportion of the hollow cylinder to permit the said valve sleeve to move rearwardly as`the' hammer approaches its rearwardlimitof movement, substantially as described. l

7. A .pneumatic motor, comprising a hollow cylinder, a valve sleeve mounted to reciprocate in. the cylinder, the cylinder and the valve sleeve having cooperating inlet and exhaust ports, a hammer located in the valve sleeve and adapted to reciprocate therein under-theinuence of the live motive fluid introduced through the ports of the cylinder and valve sleeve,"means for permitting the live motive fluid in the rear of the hammer to pass to the rear of the valve sleeve to move the latter lforwardly for shutting olf the induction to the rear of the hammer, the'motor yhaving a restricted passage in communication at its rear extremity with the -rear extremity of the hollow of the cylinder in the rear of the valve sleeve and at its forward extremity'with one of the exhaust ports of the'motor.

In'testimony whereof I affix my signature in presence of two witnesses.

. HENRY SCHUMAGHHR. Witnesses: v A. J. OBRIEN, W. R. FERRY.

Gop'ies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

